Improvement in screw-plates



UNITED STATES PATENT OEEIOE.

JOHN J ENN INGS AND GEORGE C. SWEET, OF WEST MERIDEN, CONNECTICUT.

IMPROVEMENT IN SCREW-PLATES.

Specification forming part of Letters Patent N0. 46,676, dated March 7, 1865.

ifo all whom t may concern.-

Be it known that we, JOHN JENNINGs and GEORGE C. SWEET, of West Meriden, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Screw-Plates; and we do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a longitudinal section of our invention, taken in the line w m, Fig. 2 5 Fig. 2, a transverse section 0f the same, taken in the line y y,Fig. 1.

Similar letters of reference indicate like pai ts.

This invention relates to a new and im proved mode ofsecuring the dies in screwplates for cutting screws, whereby the dies may be readily adjusted in and removed from the screw-plate, as hereinafter set forth.'

A represents a screw-plate, which may be of the usual or any proper form, and provided with a rectangular opening, a, toreceive the two dies B B', constructed as usual. These dies B B have each a groove, b, made longitudinally in them at each edge. These grooves are vof semicircular form in their transverse section, as shown clearly in Fig. 2.

C C are cylindrical pins which are fitted longitudinally in the plate A, extending entirely through it parallel With each other and the sides of the rectangular opening a. These pins C C project within the opening a about one-half of their diameter, and they are retained or held in the plate by means of pins o, which pass transversely through the plate and tit in grooves d, made in the sides of the pins and extending sufficiently far around them to admit of the pins C being turned onehalf of a revolution.

The pins C C have each a recess, e, made in them. These recesses are made in the pins directly opposite each other, and they are equal in length to one of the dies and extend into the pins to their centers-that is, the depth of the recesses e are equal to half the diameters of the pins. The recesses e, when the pins C C are fitted in the plate A, are at one end of the opening a, as shown in Fig. 1.

From the above description it will be seen that inv order to adjust the plates B B in the plateA, the pins C C are turned so that their recesses e will be within the opening a, and a diesay B/ may then be inserted in the opening a and shoved along so that its grooves b may receive the portions of the pins C at one side of the recesses e. The other die, B, is then inserted in the Opening ci, and the pins C turned so that the portions of the other at the oppositeside of the grooves may be tui ned into the grooves of B. Both dies are then secured in the opening a, and the pressure ot' the dies on the rod on which the screw is to be cutis obtained by the usual screw. (Shown in red in Fig. 1.) l

In order to remove the dies from the plate, the pins C C are turned so that their recesses e will be within the opening a, the die B being first removed, and the die B then shoved along until its edges come in line with the recesses e, when it also ma y be removed.

We are aware that pins C C have been previously used for securing dies in screw-plates, but they have been so arranged as to require removal from the plate in order to detach the dies. By our means of having recesses made in the pins, the removal of the latter from the plate is avoided, as heretofore described.

We claim as new and desire to secure by Letters Patent- The employment or use of pins C C, iitted JOHN JENNINGS. GEORGE C. SWEET.

Witnesses:

GEORGE A. FAY, ORvILLE H. PLATT. 

